I designed and printed this for a friend who wanted to build a Prusa i3 and wanted to use this dual head extruder from Makergeeks

https://www.youmagine.com/designs/mount-makergeeks-makerbot-mk9-on-prusa-i3

https://www.youmagine.com/designs/mount-makergeeks-makerbot-mk9-on-prusa-i3